屠宰前鸡、猪源大肠杆菌耐药性调查

本试验旨在了解屠宰前鸡、猪源食品动物体内大肠杆菌耐药情况,分析潜在的食品安全问题。从广州市畜禽交易市场随机采集待屠宰鸡和猪的粪便样品,分离鉴定大肠杆菌,并采用琼脂稀释法检测大肠杆菌对15种抗菌药物的敏感性。结果显示,从658份猪源样品和133份鸡源样品中共分离鉴定出731株大肠杆菌,其中猪源606株,鸡源125株。药敏试验结果显示,731株大肠杆菌均表现出不同程度的耐药,耐药谱广且多重耐药现象严重。对复方新诺明和四环素的耐药率为90.0%以上,仅对头孢西丁、黏菌素和阿米卡星较敏感(耐药率均低于3%)。鸡源大肠杆菌对头孢噻肟、头孢曲松、新霉素、阿米卡星、萘啶酸和环丙沙星的耐药率显著高于猪源大肠杆菌(P＜0.05)。鸡源大肠杆菌中3耐及3耐以上的菌株占97.60%,猪源大肠杆菌占94.72%。结果表明,屠宰前畜禽体内大肠杆菌对临床常用抗菌药物的耐药性非常严重,以多重耐药为主,且耐药谱丰富多样。提示屠宰前畜禽携带的耐药菌对食品安全和人类健康存在较大的安全隐患。     

食品动物源大肠杆菌多重耐药性监测

为掌握畜禽源大肠杆菌的耐药情况,了解其对各种抗菌药物的敏感程度,自广东地区临床分离鉴定出294株食品动物源大肠杆菌,采用琼脂稀释法测定294株大肠杆菌对14种抗菌药物的敏感性。结果显示,食品动物源大肠杆菌对各抗菌药的敏感性不同,且多重耐药现象较严重;受试大肠杆菌对四环素和复方新诺明的耐药率较高,均达到80%以上;对第3代头孢菌素类耐药率相对较低。     

800株不同动物源大肠杆菌的耐药性监测

采用微量稀释法,检测了2007年12月分离自四川省5个市的牛源、猪源、鸡源800株大肠杆菌对13种抗菌药物的敏感性.结果显示,分离菌株的耐药率除阿米卡星仅5.9%外,其余药物均超过35%,对磺胺异(口惡)唑、磺胺甲嗯唑+甲氧苄啶、氨苄西林的耐药率较高,分别为100%、96.6%、75.8%;分离菌株多重耐药情况严重,耐受3种以上药物的菌株占92.6%.不同地区及不同动物源大肠杆菌耐药水平存在差异.其中成都地区耐药性最严重,鸡源大肠杆菌耐药率最高.监测结果表明,四川省动物源大肠杆菌的耐药现状已不容乐观,有必要加强耐药性监测,指导兽医临床合理使用抗菌药物.     

凉山州不同动物源大肠杆菌耐药性调查

为了给凉山州特色畜禽临床用药及耐药性监测提供理论依据,试验采用微量肉汤稀释法对分离自凉山州不同动物的214株大肠杆菌(包括建昌鸭源80株、建昌马源72株、德昌水牛源62株)进行土霉素、阿米卡星、氟苯尼考等13种抗菌药物的敏感性试验,以确定其耐药谱型。结果表明:214株大肠杆菌耐药严重,对大部分药物耐药率达到70%以上;仅对阿米卡星、左氧氟沙星较敏感,多重耐药多集中在10~12耐。说明凉山州特色畜禽源大肠杆菌耐药情况较为严重,应增加耐药性监测力度宣传力度,指导合理用药。     

乌鲁木齐地区不同健康状态和饲养环境中宠物源沙门菌耐药特征分析

为探究不同健康状态和不同饲养环境下沙门菌对临床常用抗菌药物的耐药情况及耐药基因携带情况,采用琼脂稀释法对健康与患病、家养与流浪宠物粪样中分离出的99株沙门菌进行临床常用12种抗菌药物的耐药性检测;用PCR方法对获得的耐药菌株进行相关耐药基因的检测。结果:分离出的宠物源沙门菌对所有被检的抗菌药物耐药率均未超过10.0%,对头孢噻呋、安普霉素、阿米卡星、卡那霉素和硫酸庆大霉素100%敏感;患病动物源沙门菌对被检抗菌药物的耐药率高于健康动物源沙门菌,家养动物源沙门菌对被检抗菌药物的耐药率高于流浪动物源沙门菌(P<0.05)。耐药基因检测结果显示:floR的检出率为3.0%;ant(3″)-Ia、tetA、tetB检出率均为2.0%;blaTEM、oqxA、aac(6′)-Ib-cr基因检出率均为1.0%,未检出其他被检基因。结果表明,新疆乌鲁木齐市不同健康状态和不同饲养环境下宠物源沙门菌对被检抗菌药物的耐药率及耐药基因携带率低,仅有2株沙门菌存在ant(3″)-Ia+tetA+tetB 3种耐药基因共存情况。根据试验结果发现检出的耐药表型与耐药基因之间存在相关性,可根据药敏试验结果合理选用抗菌药物进行临床细菌病的治疗。     

1997—2010年上海市猪源大肠杆菌耐药性和产ESBLs菌的基因型检测

[目的]了解1997—2010年上海市猪源大肠杆菌的耐药情况和产ESBLs大肠杆菌的基因型分布。[方法]采用K-B法对199株猪源大肠杆菌进行药敏试验,采用PCR方法对TEM、CTX-M、SHV和OXA等4种基因型进行检测。[结果]199株猪源大肠杆菌对20种抗菌药物均表现出不同程度的耐药性。耐药率最低的为大观霉素（7.04%）,其次为头孢曲松（10.55%）、头孢哌酮（12.56%）,最高的为林可霉素（100%）,对阿莫西林和复方新诺明的耐药率分别高于80%和93.33%。5~15耐的菌株占88.94%。15种抗菌药物之间均存在不同程度交叉耐药性。共检出15株产ESBLs菌株（7.54%）,其中2株TEM型,5株CTX-M型,7株同时携带TEM、CTX-M型。[结论]上海市猪源大肠杆菌分离株耐药谱广、耐药率高;对抗菌药物的交叉耐药现象严重,交叉耐药率有的相似,有的差异大。猪源大肠杆菌ESBLs基因型主要以TEM型和CTX-M型为主,尚无SHV型和OXA型。     

上海市动物源性大肠杆菌的分离鉴定和药敏试验

为掌握上海市动物源性大肠杆菌的耐药情况及耐药规律,对2013—2015年在门诊畜禽中分离到的大肠杆菌进行药敏试验。共分离到236株大肠杆菌,其中猪源164株、禽源72株。选用15种抗生素,采用CLSI推荐的微量肉汤稀释法,对大肠杆菌进行药物敏感试验。结果表明,无论是猪源大肠杆菌,还是禽源大肠杆菌,对大多数抗生素的耐药程度均较高。其中,对磺胺异噁唑、复方新诺明、恩诺沙星和大观霉素等抗生素的耐药情况较为严重;对丁胺卡那霉素和阿莫西林/棒酸2种抗生素较为敏感,耐药率低于20%。从耐药谱型来看,猪源大肠杆菌较禽源大肠杆菌具有更加复杂的耐药谱型。     

湖南省规模化猪场猪源大肠杆菌的耐药性调查

目前兽药临床上,猪源性大肠杆菌对常用抗菌药的耐药率相当高,耐药谱也相当复杂,是目前大肠杆菌耐药的一个普遍现象。本试验应用了13种抗菌药物对湖南地区分离的58株猪源致病性大肠杆菌进行了药物敏感性试验,实验结果显示,猪源大肠杆菌分离菌株对目前常用和应用时间较长的抗菌药物,如四环素、氨苄青霉素、恩诺沙星、阿莫西林、诺氟沙星等产生了非常严重的耐药性。猪源大肠杆菌分离株对于一些新药和未大量应用于猪场的药物如安普霉素、丁胺卡那霉素等则比较敏感。因此细菌耐药性与用药情况密切相关。     

湖南省永州市规模化猪场猪源大肠杆菌的耐药性调查

为研究猪源大肠杆菌对常用抗菌药的耐药率,试验应用了12种抗菌药物对湖南地区分离的179株猪源致病性大肠杆菌进行了药物敏感性试验。试验结果显示,猪源大肠杆菌分离菌株对目前常用和应用时间较长的抗菌药物,如四环素、氨苄青霉素、恩诺沙星、阿莫西林、链霉素等产生了非常严重的耐药性。猪源大肠杆菌分离株对于一些新药和未大量应用于猪场的药物如安普霉素、丁胺卡那霉素等则比较敏感。细菌耐药性与用药情况密切相关。     

广东地区猪源大肠杆菌耐药性及其系统发育群的研究简

为分析广东地区猪源大肠杆菌耐药性及其系统进化背景,试验于2011年从患病猪分离出264株大肠杆菌,包括粪便源131株和肝源133株,采用琼脂稀释法测定18种抗菌药物的敏感性,多重PCR法确定系统进化关系,并对不同来源菌株的耐药性和系统进化背景进行分析比较。结果发现,大肠杆菌多重耐药现象严重,共存在128种耐药谱型。分离菌株对氨苄西林、复方新诺明、萘啶酸和四环素高度耐药,对黏菌素、头孢他啶和阿米卡星较敏感。种群进化分析结果表明,分离菌株主要分布在共生型的A组和B1组（91.66%）,且不同来源菌株的种群进化分布差异不显著(P＞0.05)。结合药敏试验结果发现,不同进化组别的分离菌株对特定抗菌药物的耐药性存在显著差异（P＜0.05）。通过对大肠杆菌耐药性及其系统发育群进行综合分析,为兽医临床用药提供依据。     

种鹅大肠杆菌分离鉴定及耐药性分析

为了解种鹅致病性大肠杆菌病的病原及其药物敏感性,2012年从广东地区患病种鹅器官和粪便中分离鉴定了62株大肠杆菌,采用琼脂稀释法测定了大肠杆菌对17种抗菌药物的敏感性。结果发现大肠杆菌耐药性严重,对大部分药物的耐药率超过60.0%,仅对头孢西丁、头孢他啶和黏菌素较敏感。联合药敏试验结果显示多西环素和氟苯尼考联用对耐药大肠杆菌产生协同抑菌作用,FIC指数为0.375～0.75。采用脉冲场凝胶电泳（PFGE）法对24株大肠杆菌进行分型,结果分为17种不同的PFGE型别。大肠杆菌系统进化分群结果显示43.5%属于系统进化组群的D组,其次是A组和B1组,分别为34.8%和21.7%,B2组未检测到。通过对种鹅大肠杆菌耐药性、PFGE分型及其系统发育群进行综合分析,为临床用药提供了参考依据。     

Drug resistance in strains of Escherichia coli isolated from the intestinal tract of pigs in Norway.

Faecal samples from 95 healthy pigs and samples of jejunal content from 85 piglets suffering from colienterotoxaemia were tested for the presence of drug resistant E. coli strains. Practically all pigs in both groups harboured E. coli strains resistant to one or more of the 6 antibiotics/chemotherapeutic agents tested (Oxytetracycline, streptomycin, sulphaisodimidin, neomycin, ampicillin, chloramphenicol). Almost 100% of healthy and approx. 90% of diseased pigs harboured strains resistant to Oxytetracycline, streptomycin and sulphaisodimidin. Pigs with strains resistant to neomycin, ampicillin and chloramphenicol were less frequently found. The predominant coliform flora consisted of E. coli strains” resistant to Oxytetracycline, streptomycin and sulphaisodimidin in 71% to 81% of diseased pigs and in 47% to 69% of the healthy pigs. In diseased pigs ¾ of the animals had a coliform flora dominated by neomycinresistant E. coli strains.Of the 721 resistant E. coli strains isolated from healthy pigs, 11% were single resistant while the corresponding figure for the 518 resistant strains isolated from diseased pigs was 6%. Thus 89% and 94% of strains showed simultaneous resistance to 2 or more antibiotics. E. coli strains resistant to 3 or more drugs were found in approx. 60% and 70% of the isolates from healthy and diseased animals, respectively. Oxytetracycline/streptomycin/sulphaisodimidin resistance was most commonly found, approx. 22% and 38% of the strains from healthy and diseased pigs, respectively, showing this resistance pattern.Transmission of drug resistance which was examined in E. coli strains originating from the diseased pigs was demonstrated in approx. 76% of the isolates. The incidence of drug resistance transfer in single, double, triple and quadruple resistant strains was 11%, 68%, 97% and 98%, respectively.     

Study on Drug Resistance of Escherichia coli Isolated from Chicken and Swine in Organic Farm

To determine the drug resistance of E.coli strains from swine and chicken in organic farm,collection of stool specimens was conducted in one organic farm in Conghua city,Guangdong province in 2014,in which 118 E.coli strains were separated,including 55 from chicken and 63 from swine.The sensitivity of the E.coli strains from swine and chicken to 18 kinds of drugs was detected through agar dilution method.Similar properties in drug resistance were observed both in E.coli strains from swine and chicken in the same organic farm.In consideration of the resistance rate,samples were relatively sensitive to ceftazidime,cefquinome,cefoxitin,amikacin,apramycin,gentamicin,neomycin,florfenicol,chloramphenicol,imipenem,ciprofloxacin and olaquindox (chicken 0 to 21.8%;swine 0 to 14.3%).These isolates showed moderate resistance to ampicillin and streptomycin (chicken 29.1% to 38.2%;swine 23.8% to 27.0%).About 56.4% chicken isolates and 47.6% swine isolates showed resistant to more than 3 kinds of drugs.However,severe resistance was observed in trimethoprim-sulphamethoxazole,tetracyclineand and doxycycline (chicken 45.5%,76.4% and 72.7%;swine 50.8%,81.0% and 68.3%).The results also indicated that under organic farming mode,the drug resistance rates of E.coli strains from swine and chicken were relatively low in general.Multi-drug resistance existed but was relatively slight.Although the drug resistance rate to several specific antimicrobials was high,it was still lower than that in conventional farms.Since most studies focused on the drug resistance of the bacteria under conventional farming model,this study filled the blank of the research of drug resistance under organic farming model.     

有机农场鸡、猪源大肠杆菌耐药性研究

为了解有机养殖模式下鸡、猪源大肠杆菌的耐药情况,2014年从广东从化某有机农场鸡、猪粪便中采集并分离出118株大肠杆菌,包括55株鸡源大肠杆菌和63株猪源大肠杆菌,采用琼脂稀释法测定大肠杆菌对18种抗菌药的敏感性。结果发现,同一有机农场中,鸡源大肠杆菌与猪源大肠杆菌在耐药种类及耐药率上均呈现相似规律,对头孢他啶、头孢喹肟、头孢噻肟、头孢西丁、阿米卡星、安普霉素、庆大霉素、新霉素、氟苯尼考、氯霉素、亚胺培南、环丙沙星、喹乙醇等较敏感(鸡0~21.8%,猪0~14.3%),对氨苄西林、链霉素呈现轻度耐药(鸡29.1%~38.2%,猪23.8%~27.0%),对复方新诺明、四环素、多西环素呈现较严重耐药(鸡45.5%、76.4%和72.7%,猪50.8%、81.0%和68.3%)。鸡源大肠杆菌中3耐及3耐以上的菌株占56.4%,猪源大肠杆菌占47.6%。结果表明有机养殖模式下鸡、猪源大肠杆菌耐药率相对较低,多重耐药现象存在但相对轻微,对个别临床常用抗菌药耐药率虽较严重但比常规养殖场低。由于目前国内大部分学者致力于研究常规养殖方式下细菌耐药情况,本研究很好地填补了有机养殖模式下畜禽大肠杆菌耐药性研究的空白。     

Association between antimicrobial treatment and resistance of pathogenic Escherichia coli isolated from diseased swine in Kagoshima Prefecture,Japan

Pathogenic Escherichia coli is an important cause of diarrhea, edema disease, and septicemia in swine. In Japan, the volume of antimicrobial drugs used for animals is highest in swine, but information about the prevalence of antimicrobial-resistant bacteria is confined to apparently healthy animals. In the present study, we determined the O serogroups, virulence factors, and antimicrobial resistance of 360 E. coli isolates from swine that died of disease in Kagoshima Prefecture, Japan, between 1999 and 2017. The isolates of the predominant serogroups O139, OSB9, O149, O8, and O116 possessed virulence factor genes typically found in diarrheagenic E. coli. We further found five strains of third-generation cephalosporin-resistant E. coli that each produced an extended-spectrum β-lactamase encoded by bla_CTX-M-14, bla_CTX-M-15, bla_CTX-M-24, bla_CTX-M-61, or bla_SHV-12. In 218 swine with a clear history of antimicrobial drug use, we further analyzed associations between the use of antimicrobials for the treatment of diseased swine and the isolation of resistant E. coli. We found significant associations between antimicrobial use and selection of resistance to the same class of antimicrobials, such as the use of ceftiofur and resistance to cefotaxime, cefazolin, or ampicillin, the use of aminoglycosides and resistance to streptomycin, and the use of phenicols and resistance to chloramphenicol. A significant association between antimicrobial use and the resistance of E. coli isolates to structurally unrelated antimicrobials, such as the use of ceftiofur and resistance to chloramphenicol, was also observed.     

新疆伊犁某牛场大肠杆菌耐药性调查

为了调查新疆伊犁某牛场饮水、饲料和粪样中分离的大肠杆菌对临床常用抗菌药物的耐药情况。本试验采用微量肉汤稀释法,对饮水源、饲料源、牛粪源样品中分离出的大肠杆菌进行最小抑菌浓度测定。结果显示,25份牛场饮水源样品,大肠杆菌分离率为100.0%（25/25）,对阿莫西林/克拉维酸（12.0%）、氨苄西林（4.0%）、诺氟沙星（4.0%）、恩诺沙星（8.0%）和安普霉素（8.0%）5种抗菌药物耐药;72份牛场饲料源样品,大肠杆菌分离率为65.3%（47/72）,对阿莫西林/克拉维酸（36.2%）、氨苄西林（19.1%）、诺氟沙星（4.3%）和安普霉素（4.3%）4种抗菌药物耐药;80份牛粪源样品,大肠杆菌分离率为100.0%（80/80）,对阿米卡星（12.5%）、氨苄西林（7.5%）、恩诺沙星（7.5%）、庆大霉素（5.0%）、诺氟沙星（2.5%）、环丙沙星（2.5%）、阿莫西林/克拉维酸（1.3%）和头孢噻呋（1.3%）8种抗菌药物耐药,仅对安普霉素敏感。该牛场分离的大肠杆菌对常用抗菌药物耐药情况一般,但中介率较高,须在临床治疗细菌性疾病中避免使用不敏感和中介率高的抗菌药物,养殖场饮水和饲料有被耐药大肠杆菌污染的风险。     

奶牛子宫内膜炎源性大肠埃希菌药敏试验与耐药基因检测

为探索奶牛子宫内膜炎源性大肠埃希菌耐药基因及其耐药性之间的关系。采用K-B纸片法对临床分离的54株奶牛子宫内膜炎源性大肠埃希菌进行12种抗菌药物敏感性测定,应用PCR进行这些抗菌药物相关耐药基因的检测。结果显示,54株大肠埃希菌对复方新诺明、恩诺沙星和四环素的耐药率较高,分别为67%、39%和35%。分离的54株大肠埃希菌中有41株至少含有所检测耐药基因中的1种,CyrA、CyrB、ParC和Tet耐药基因较为普遍,其耐药菌基因检出率依次为96%、83%、100%和95%,13株没有检测到相应的耐药基因。奶牛子宫内膜炎源性大肠埃希菌对常见抗菌药物耐药严重,耐药基因普遍存在于耐药菌株中,除氨基糖苷类耐药菌株,其他3种抗菌药物类型耐药表型与耐药基因检测结果有较高一致性。